Month: November 2013

Almost three quarters of the British population participate in gambling of some form, despite the fact that we know the odds are so heavily stacked against us. So why do we gamble despite the massive risk?

The answer to this question lies in the biology of our brains; exactly how does the brain change during addiction? Circuits known as the ‘reward system’ connect to regions of the brain involved in memory, pleasure and motivation. When we enjoy something these neurons release dopamine, a chemical neurotransmitter that makes us feel happy, a feel-good chemical that makes us satisfied and encourages us to continue our habits. This is similar to what happens in the brains of drug addicts.

A collaboration between Drs Luke Clark from the University of Cambridge and Henrietta Bowden-Jones from the only NHS clinic for gambling addicts is trying to address what makes some of us so hooked on gambling and what happens in our brains. We know that there are both external and internal factors that influence our gambling habits such as our personality type, neurobiological and neurochemical make-up, as well as the different features of the games themselves.

Using a number of control and ‘gambler’ subjects, behavioural tests looked at impulsivity, compulsivity and dopamine levels. As suspected, gamblers were more impulsive than controls; something which is mirrored in drug addicts and alcoholics. Brain imaging studies have shown that near-misses recruit areas of the brain that are associated with winning. The ‘near-miss’ phenomenon is the theory that losing a game acts as an aversive stimulus- it actually puts us off gambling. But, coming close to winning acts to fuel our desire to gamble. The fact that the same areas are activated when we almost win, and when we actually do win may encourage us to gamble – and this is something that can be exploited by game manufacturers.

Is the degree of brain activation during winning related to gambling severity? Subjects were asked to play on a slot machine whilst an fMRI machine measured brain activity in response to the game (functional magnetic resonance imaging- looking at the level of blood flow to areas of the brain in response to stimuli). Results found that those subjects with severe gambling addictions had the greatest activity in their midbrain in response to near-misses, but the activity to a real-win did not differ with gambling severity. This brain region is of interest because dopamine is produced here, and is implicated in other addictive behaviours such as alcoholism.

This leads us to ask if there is a chemical basis to gambling addiction. Well, scientists know that there are a decreased number of dopamine receptors in the brains of drug addicts, but is this mirrored in the brains of gambling addicts? Surprisingly, although there were no differences overall in the amount of dopamine receptors in gamblers compared to controls, gamblers that were more impulsive did have a lower number of dopamine receptors. Strikingly, when they studied the gambling behaviour of patients who had suffered a brain injury, the ‘near-miss’ response observed in gambling addicts was not seen in patients that had damage to their insula. The insula may be central to the distorted thinking patterns seen in gamblers.

Compulsive gamblers are not necessarily greedier than the rest of us, but their brains may be wired differently. Gamblers are more likely to prioritise money over other basic needs such as food and social interactions. Perhaps there are changes in a gamblers brain that render them hyper-sensitive to the ‘rush’ of winning. On the flip-side, it is possible that pathological gamblers are less sensitive to the things that the rest of us would find rewarding, such as alcohol or sex.

Taken from Ted Murphy

Healthy controls and pathological gamblers were put into an fMRI scanner to record brain activity during a task where they had to press a button in response to money-based or sexual images. The faster the button was pressed, the more motivated the subject was to get the reward. Despite stating that they found both money and sex equally rewarding, results found that gamblers pressed the button 4% faster when viewing money-related images than sexual images. Indicating that gamblers attributed a higher value to money than sex. The gambling cohort had increased blood flow to the ventral striatum (part of the brain involved in reward processing) in response to monetary images, more than to sex. In contrast, no difference was found in the controls. Interestingly, they found altered activity in the orbito-frontal cortex of gamblers, which is also involved in reward processing. Past studies have shown that different parts of the orbito-frontal cortex are activated in healthy individuals in response to money and erotic images- which is thought to reflect the dissociation between rewards that are vital to survival such as food and sex, and secondary rewards such as money and power. In gambling addicts, the same region of the orbito-frontal cortex was activated in response to sex and money, suggesting that they have an altered perception of money as a more primal reward.

A large proportion of future work will focus on uncovering the precise role of the insula in addiction by observing how its activity changes whilst gambling. Another area of interest is looking at relatives of gambling addicts, and trying to identify if differences exist in both their brain activity and also in their behaviours when gambling. This may be of huge importance as therapies and treatments may be able to focus on targeting affected areas of gamblers’ brains.

A US company, Backyard Brains, has recently been criticised for marketing a device which allows users to create their own ‘cyborg’ cockroach, using a mobile phone app to control the critter’s movements. The ‘kickstarter’ funded project, headed by graduate students with a passion for science education, has caused serious controversy, including accusations that the device will “encourage amateurs to operate invasively on living organisms” and “encourage thinking of complex living organisms as mere machines or tools”. But is it possible that these concerns are misguided?

As a scientist with a passion for public engagement, on many occasions I’ve struggled with two fundamental and opposing concepts which make this work a very delicate balancing act:

Science is complicated and often a bit dry.

If you want to engage non-scientists, it is often necessary to ‘sex things up’ with provocative language and concepts which pique their interest.

And here lies the problem.

Let’s take Backyard Brains’ ‘RoboRoach’ as an example. The students who began this project noticed a fundamental problem: “One in five people are likely to suffer from a neural affliction at some point in their lives and many such disorders are currently untreatable. Thus, we are in desperate need of more research in this area”. However, unlike chemistry, physics and some other aspects of biology; there are no hands-on ways to engage young people with neuroscience.

This means that when most budding neuro-researchers reach university (myself included), they are often woefully unprepared for the work they will be doing. I still remember struggling with the concepts of electro-chemical gradients and the technology used to record signals from the living brain. After 8 years I’d say I’m finally getting there. But, with our lab looking into early Alzheimer’s diagnostics and treatments, I can’t help but wish I had been better prepared to move quickly into this complicated and immensely important field of study.

The Backyard Brains tool kit certainly ticks all the boxes as a cheap, easy to use method to teach future scientists. And I don’t doubt that the procedures they use balance causing the least possible harm with giving young scientists a chance to learn things they would otherwise not encounter until late in their university education. So I have no qualms with the premise behind ‘RoboRoach’. But I do see a problem with how this teaching tool has been marketed. Terms like ‘RoboRoach’ and ‘cyborg’, not to mention this t-shirt, cheapen the premise behind this project and give critics ample fodder to argue that these scientists are heartless and happy to make light of (and profit from) a serious matter.

So this is where my earlier points come into play. I understand why Backyard Brains used this marketing technique. I’ve been to a number of public engagement lectures where one message is constantly driven home: if you want people to care about your scientific work, you have to make it sound “cool”. So, to be honest Backyard Brains are following this message to a tee. If you read through their web page they even admit this:

“The name “The RoboRoach” and the tagline “Control a Living Insect from Your Smartphone” was chosen to be provocative and to capture the public’s interest. A more accurate though much drier title would have been: “The RoboRoach: Study the effect of frequency and pulse duration on activating sensory circuits in the cockroach locomotion system, and the subsequent adaptation.” This is an accurate description, and these devices are currently used by scientists at research universities. However, such a description though would have alienated novices who have never had any exposure to neuroscience or neural interface experiments. We aim to bring neuroscience to people not necessarily in graduate school and thus chose an easily understandable, provocative name.”

However, I also understand why critics have called their stance ‘disingenuous’, especially when their website contains honest, well argued, ethical considerations alongside seemingly flippant statements which appear to trivialise the whole project; like this: “The RoboRoach is the world’s first commercially available cyborg! That’s right… A real-life Insect Cyborg! Part cockroach and part machine” – statement from their kickstarter page.

Unfortunately, although this marketing may have bought them funding, it has also cost them the trust of many critics.

But if you can step outside the controversy and look at the basics of this project, I do believe that this work is both timely and necessary. Here, budding researchers learn how nerve cells communicate and, on a basic level, how to interface with a living brain. The techniques they learn are similar to those used in deep brain stimulation for treatment of Parkinson’s disease; a procedure which has given many sufferers a whole new lease of life! (see video below) And, to top it off, the cockroaches in question continue on to live a full life following the experiments (a fate preferable to that of most wild roaches).

So, although I certainly understand the criticisms aimed at this product. I also honestly believe that, if used as intended as an academic tool, this kit could be an important first step in training future neuro-researchers; perhaps even giving them the head start they need to cure some of the most devastating neurological afflictions.

Bees are great. They have an amazing social hierarchy, they provide medical care for their sick, they have ruthless security ‘bouncer-bees’ and each bee travels huge distances to gather about one twelfth of a teaspoonful of honey. For us humans, the benefits of bees don’t stop at honey. About a third of our crops – approximately $220 billion-worth globally – are inadvertently pollinated by foraging bees and, from what I’ve heard, we really don’t want to have to start doing that ourselves.

The problem is that bees are dying at an alarming rate. As it happens, my father is a budding bee-keeper and has just received a letter from the Food and Environment Research Agency that reports a halving of honey production in South-East England in the last six years alone. This problem is, however, happening all over the world. Imaginatively dubbed ‘colony collapse disorder’ (CCD), a mystery disease is wiping out huge numbers of bees yet no one can pin down exactly what the cause is. There are several theories, so I’ve taken the liberty of making a list akin to a ‘Top Six Most Wanted Villains’ of the bee world.

A varroa mite feeding on a honeybee (Wikicommons)

Varroa mites: Affectionately known as ‘vampire’ mites, these teeny-weeny bugs are big trouble. They suck hemolymph (the bee’s version of blood) from honeybees and, in so doing, weaken the bee and may even transmit deadly viruses (more later).

Neonicotinoids and other pesticides – Neonicotinoids (NNs) are chemicals designed to kill insects that feed on farmed crops. They bind to acetylcholine receptors on the cells of the insect’s nervous system, eventually blocking their normal use, causing paralysis and death. In the past couple of years, various research groups have shown that these chemicals get into bee hives at dangerous, though not lethal concentrations. Not only that, but a paper published in Nature showed that a cocktail of these chemicals may lead to CCD by affecting bee behaviour, presumably through their effects on the bees’ brains. Bees affected by these chemicals tend to forget where they are in relation to the hive, and produce less food. Other research has shown that NNs may affect the way that bees metabolise their food to produce energy. Scientists have even shown that exposure to NNs affects an important immune defence pathway, which may make bees more vulnerable to parasites and viruses.

Viruses: Viruses such as Israeli acute paralysis virus, deformed wing virus and acute bee paralysis virus are spread by varroa mites and have all been identified as possible causes of CCD. Deformed wing virus is particularly tragic; if pupae are infected and develop wing deformities, they are kicked out of the colony, and the number of healthy bees dwindles. Israeli acute paralysis virus has been shown to interfere with the bees’ cellular machinery that produce proteins.

Nosema – this is a fungus that causes intense diarrhoea when swallowed by a bee, leading to worker bees pulling a sickie, which means less food for the hive. To add insult to injury, the queen bee becomes infertile and the colony stops producing young.

Malnutrition – Bees that collect their food from a variety of sources tend to be more hardy and resistant to infection than those that rely on only one or two types of flowering plant. In the US where farms cultivating one or two crops such as wheat or corn are vast, bees may become malnourished and more susceptible to disease.

Parasitic phorid fly – Last year, a researcher found a phorid fly larva in a test tube containing a honeybee that had died from suspected CCD. Phorid flies (which apparently scuttle more than they fly) lay eggs on the bee’s abdomen, which then hatch and feed on the bee. Weirdly, bees that carry this parasite end up acting more like moths than bees (foraging at night, buzzing around bright lights) before abandoning the hive.

What’s most likely is that CCD is caused by a mixture of two or more of the culprits mentioned above working in tandem. For example, varroa mites weaken bees and give them viruses. While a colony may be able to withstand either the mites or the virus, the two knocks together could be lethal. This interplay between several different factors makes it all the more difficult for scientists and beekeepers to research and prevent CCD.

So what’s being done to stop all the bees dying? Aside from all the tried and tested treatments for the parasites and viruses known, there are new efforts to save the bees via various industrial collaborations. Earlier this year, Monsanto set up its own Honey Bee Advisory Council including scientists, beekeepers, industrial and governmental representatives to try and tackle the issue. In 2011, Monsanto also bought Beeologics, a company in Israel that researches possible solutions to CCD. One strategy used by Beeologics against bad viruses is to deliberately infect bees with a special artificial ‘good’ virus. In turn, this good virus infects any varroa mites feeding on the bee. Amazingly, this good virus acts to prevent the mites from being able to pass on bad viruses to the bee. This treatment is currently passing through regulatory tests, but it will hopefully represent the start of a new approach to keeping bees alive for the benefit of humanity – and not just for the honey.

If there are two things that pique my interest in life, it’s Biology and dogs (specifically pugs). So imagine my delight when I saw that there was an actual research paper in Current Biology all about dogs [1]. The study showed that dogs can communicate their emotions with other canines through tail wagging. It has already been shown that tail wagging to the left is linked to anxiety while wagging to the right is linked with more positive emotions [2]. What this new study showed was that dogs can actually respond to the left- or right-tail wagging of other pooches. It is thought that this behaviour is linked to the processing of different social queues in different sides of the brain [1,2].

This is a pretty relaxed Basset Hound.

In this study dogs were shown movies of other dogs wagging their tails more to the left or more to the right and the viewing dogs’ heart rate and behavioural reactions were recorded. The same experiment was also repeated with a silhouette of another dog, to reduce other social queues like facial expression. The results showed that the heart rates of dogs shown left-wagging went up, a sign of anxiety, while dogs shown right-wagging had a lower heart rate and relaxed behaviour.

Interestingly, when the canines were shown a movie of a still dog they had higher levels of anxiety than when shown a movie of a right-wagging dog. The authors proposed this may be due to confusion as the dogs tried to work out what the dog in the movie was doing or that this might be linked with human responses to neutral faces: in experiments where people were shown faces with neutral expressions they tended to assign negative emotions to them [3]. Perhaps like the humans, these were pessimistic pooches.

These results are interesting in terms of understanding the nuances in social communication between dogs but also hint at something relatable to other animals. They also support the notion that processing of certain social situations can favour one side of the brain over the other. This may well help us understand our own brains better and aid research into how the brain responds to different emotions. All I know is, there should be more serious scientific studies that have this in the supplementary figures…